A known injection valve of this type (International Application No. WO 93/23 172) for injecting fuel directly into the combustion chamber of an internal combustion engine comprises a valve body disposed inside a valve housing and having a valve opening, which is surrounded by a valve seat on the spraying side, and through which a valve needle that supports a closing head extends such that, when the valve is closed, the closing head rests with its sealing surface against the valve seat from the outside. When the valve is open, that is, when the closing head of the valve needle is lifted from the valve seat in the direction of injection, the outlet opening defined between the valve seat and the sealing surface forms an injection opening, which adjoins an annular gap provided in the end region of a flow path for fuel through the injection valve, and which represents the smallest cross section in the flow path for the fuel dosing.
In another known injection valve (U.S. Pat. No. 5,058,549), a valve needle having a closing head is disposed inside a housing. The closing head has a conical sealing surface, which cooperates with a valve seat provided in front of an injection opening arrangement with respect to the direction of injection. Provided behind the valve seat, in a dome-shaped housing section, are a primary and a secondary injection opening, which allow fuel to be injected into the primary region as well as into the region of a combustion chamber in which the spark plug is disposed.
In another known injection valve (German Patent Application No. DE 43 28 418 A1), a nozzle plate is disposed in the valve housing behind a valve seat that cooperates with a valve needle, the plate having a retaining plate with a stepped, throughgoing bore in which an injection plate is inserted. Provided in the spray-side edge region of the injection plate is a recess which, together with an associated recess on the retaining plate, forms an annular channel whose outlet-side edges define an annular outlet gap on the holding and injection plates, which forms an injection opening with a dosing function. The annular channel of this known injection plate is connected to the supply side of the nozzle plate via slots provided in the injection plate such that the fuel flowing into the annular channel is equally distributed and can be injected in the circumferential direction as identically-shaped fuel sheets.